Refined hydrocarbon oil



Fatented Mar. i9, 19%

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ration of Indiana No Drawing. Application June 13, 1938,

Serial No. 213,447

7 Claims.

This invention relates to the method of stabilizing highly refined mineral oilproducts during storage and use. In particular, the invention is concerned with the inhibition of the formation of. acids, color and odor in petroleum white oils. The invention also embodies the new composition of matter resulting from the process.

White oils are prepared by the successive treatment of a heavy mineral oil with fuming sulfuric acid. These white oils have difierent viscosities,

generally, ranging from 80 to 400 seconds Say- -bolt at 100 F. and they consist almost entirely of saturated compounds.

In the use of highly refined viscous hydro- 15 carbon oils for the lubrication of turbines, ice machines and the like, it has been found that they rapidly discolor, become increasingly acidic and their tendency to emulsify also increases. Heretofore, organic materials, such as hydro- 20 quinone, gallic acid, pyrogallol and di-phenyl amine have been used to inhibit the deterioration of refined viscous white 'oils during storage and use but in many 'cases such compounds have failed to maintain their stabilizing efiect during 25 prolonged use.

The present invention is concerned with the method of stabilizing refined mineral oils against deterioration by incorporating therein a type of material which will impart a very high stability 30 under all operating conditions. The exact composition of the stabilizing agentis unknown but it is prepared by reacting chlorinated petroleum wax with about an equal amount of certain hydroxy compounds in the presence of a Friedel- 85 Crafts catalyst. I have found that when chlorinated wax is chemically condensed with naphthols, such as alpha or beta naphthol, or polyh'ydroxy-benzenes, such as catechol, pyrogallol or hydroquinone, in the presence of a Friedel 40 Crafts catalyst, such as aluminum chloride, a

product is obtained which is very effective in small quantities in inhibiting the deterioration of refined viscous white oils.

The chlorinated paraflin wax which is used in 5 preparing the inhibitor is prepared by melting parafiin wax and then passing into this molten wax a stream of. chlorine gas. Any parafiln wax or petrolatum may be used in the preparation of the chlorinated product but I preferto use par- 50 afin wax having a melting point within the range of 120 to 150 F. The chlorination of the wax is effected at a temperature above about 190 F. but preferably within the range of 206 to 250 F., and chlorine is passed into the heated wax until it has combinw with about 12 to 1% of chlorine.

The chlorinated paraflin wax has a lower melting point than the unchlorinated wax and advantage may be taken of this fact in the separation ofthe desired chlorinated constituents. One method of separating the desired chlorinated 5 wax constituents from the unreacted wax is by the sweating process in which a fractionation of the components of the wax results from the differences in the melting points of such constituents. In conducting a sweating operation, the mixture of chlorinated wax and unreacted wax is pumped in a molten state onto a plurality of trays located within a sweating oven, which is heated by means of steam or warm water coils. When the desired quantity of wax is introduced, 15 the wax is solidified by the circulation of cool water throughout the oven. The temperature of the oven is then increased by the circulation of warm water through the coils and the temperature raised to-that at which the lowest melting constituent in the wax will melt and separate from the body of the wax. It has been found that the more highly chlorinated constituents have a lower melting point than the less completely chlorinated constituents and that by submitting wax which has been treated with chlorine to a sweatingoperation, such as just described, the fraction consisting mostly of di-chloro-wax derivatives will be'separated from the unchanged wax and other'chlorinated constituents.

For examplea paraflin Wax having a melting point .of about 130-140" F. was chlorinated at 250 F. until it contained about 14% chlorine and then passed to the sweating oven for fractionation. After the wax had solidified in the sweating oven, the temperature was raised to about 65-70" F. at which temperature a fraction consisting mostly of di-chloro-wax derivatives separated from the higher melting constituents. After separating this fraction of chlorinated wax (usually called drips) the temperature of the oven was increased by the circulation of warm water through the coils and the temperature raised to that at which the undesirable waxy constituents become molten. This molten wax is then removed from the oven and recycled to the chlorination step for further chlorination. In general, I prefer to use the fractions of chlorinated wax that melt within the range of to 95 F. However, by using the chlorinated wax fraction or drips obtained from the sweating step within the temperature range of to F., a better inhibitor can be prepared by the method hereinafter described, because this fraction contains a very large proportion of the desirable chlorinated products such as the di-chloro-wax derivatives. Any fraction of the chlorinated wax having a melting point between 60 and 95 F. may be used in the condensation reaction, for example, the fraction of chlorinated wax may melt between 70 and 80 F., or 75 and 85 F., or 80 and 95 F. The higher melting fractions or drips contain larger quantities of the monochlor wax derivatives. r

Other methods may be used to separate the chlorinated wax from the unreacted wax, for example, by fractional crystallization from 501:- vents, solvent extraction and the like.

The inhibitor is prepared by reacting about equal proportions of. the chlorinated wax and naphthol or polyhydroxy, benzene in the presence of a Friedel-Crafts catalystysuch as A1013, at about room temperature. Usually a temperature of '75-95 F. is adequate to effect the ree action, although .higher temperatures may be used. The following example. illustrates the method used to prepare the condensation product.

Example I 200 grams of the chloro-wax drips (separated at a sweating temperature of 65-70 F.) were' mixed with 200 gramsof beta naphthol. While stirring or agitating this mixture, 100 grams of aluminum chloride were added thereto over a period of approximately one hour and the -resulting mixture was then stirred for a period of. approximately twenty-four hours to permit further reaction. The entire process was performed at a temperature between '75-85 F. The reacted products were neutralized with a strong caustic solution and then diluted with about an equal volume of hexane. The desired condensation product is soluble in hexane and by stirring the neutralizedreacted products with hexane, substantially all of the desired condensation product will dissolve therein. The hexane solution is then drawn on and the hexane evaporated from the desired product. The yield of liquid condensed product,'after evaporation from the hexane, was 200 grams. The product was a clear brown,' viscous oil.

In the above example, the caustic treatment not only neutralizes the hydrochloric acid but'it dissolves the excess or unreacted beta naphthol. While other alkaline materials,-such as sodium carbonate and ammonia, could be used to neutralize the reacted products, the preferred method is to use an aqueous caustic solution in order to remove the unreacted naphthol. The desired condensation product may be extracted from the reacted products by any' suitable method such as by successive extraction, percolation and the like. If desired, a portion of the white oil to be stabilized with the condensation product may be used to extract it from the reacted mass. The concentrated solution is then added to a large quantity of oil in amounts suflicient to give the desired concentration of inhibitor. It is apparent, therefore, thatv other hydrocarbon materials, such as refined kerosene and somewhat heavier mineral oils maybe used in.

the place of hexane.

While in the above example I used equal pro.- portions of the chlorinated wax and beta naphthol. it should be understood that other proportions of the reactants may be used. However, I prefer to react from /2 to 1 parts of the chlorinated wax with about one part of the phenolic compound because such proportions of the reactants give a product which is very effective in. re-

tarding the deterioration of white oils during storage and use as compared to the type of condensation product obtained -by reacting large -the, formationpf acids in white oils during *use or storage. The data set forth in the following table illustrate the effectiveness of the herein described condensation products in retarding acid formation in white 0115. The test was carried out by heating a 500 cc. sample of white oil in the presence of polished iron wire to a temperature of 210 F. Preferably, the oil is placed in a liter round-bottom flask and immersed in a constant temperature bath. Oxygen saturated with water is bubbled through the oil during the heating period at the rate of about two bubbles per second. The stability of the oil is stated as the number of hours required for the formation of one milligram of acid per gram of 011.

Table I Time in hours required for the formation of 1 mg. of

. acid per gram of oil White oil containing no inhibitor 50 White oil plus .01% of wax beta naphthol (product formed according to Example I above) 320 It is apparent from the above data that condensation products of the type herein described are very effective in stabilizing white oils. .These condensation products may be used in concentrations ranging from 0.04 to 0.0001%, however, I prefer to use these condensation products in concentrations ranging from 0.01 to 0.001%.

In addition to the type of Friedel-Crafts catalyst hereinbeforedescribed, I may also use ferric chloride. Also, small amounts of hydrogen chloride-may be used along with the aluminum chloride or ferric chloride to, promote the reaction. The other'metallic halides which are commonly used in a Friedel-Crafts type of reaction may also be used in preparing the herein described condensation products.

The'composition of the condensation product of the type herein described is not clearly under: stood but it is believed to be a high molecular weight phenolic compound. a

While I have described in detail preferred embodiments of my invention, it is to be understood that it is not restricted thereto except as set forth in the appended claims.

I claim:

1. The method of preventing the deterioration of refined mineral oils, which comprises dissolving in said oil less than 051% of a product formed by -condensing, with a Friedel-Crafts catalyst, chlorinated paraifin wax with a compound selected from the group consisting of naphthols and polyhydroxy benzenes.

2. The method of preventing acid formation naphthol in the presence of aluminum chloride.

3. The method of preventing acid formation in petroleum white oils, which comprises dissolving in said oil less than .04% of a product formed by condensing chlorinated paramn wax with catechol in the presence of aluminum chloride.

4. The method of preventing the deterioration of petroleum white oils, which comprises dissolving in said oil less than .04% of a product formed by condensing, with a Friedel-Crafts catalyst, a fraction of chlorinated p'araflin wax melting between and 95 F. with a compound selected from the group consisting of naphthols and polyhydroxy benzenes.

5. The method of preventing acid formation in petroleum white oils, which comprises dissolving in said oil a small amount of a product formed by condensing a fraction of chlorinated paraflin wax melting between and F. with a compound selected from the group consisting of beta naphthol and catechol.

6. The method of preventing acid formation in petroleum white oils during storage, which comprises dissolving in said oil from 0.04 to 0.0001% of a product formed by condensing, with a Friedel-Crafts catalyst, chlorinated paraflin wax with a compound selected from the group consisting of naphthols and polyhydroxy benzenes.

7. A composition of matter comprising petroleum white oil and from 0.04 to 0.0001% of a product formed by condensing, with a Friedel- Crafts catalyst, chlorinated parafiin wax with a compound selected from the group consisting of naphthols and polyhydroxy benzenes.

CLARENCE M. LOANE. 

